Color sound film



June 17, `1941. K 'scHlNzEL ETAL 1 2,246,013

COLOR SOUND FILM Filed June 18, 193B ExPosuRE .0E PICTURE AREA HHHHT /5\ fof.

AETER DEVELOPMENT 0E -R/ cTuRE AREA SOUND TRACK Af TER DEVELOPMENT of souND TRAcR AND REMOVAL of .s/L VER; .SILVER HAL/DE AND -f/LTER Adevelopedy before the scenes.

Patented June 1,7, 19.41

COLOR SOUND FILM Karl Schinzel, Rochester, N. Y., and Ludwig Schinzel, Troppau, Silesia; said Karl Schinzel assignor to Eastman Kodak Company, Rochester, N. Y., a corporation ol New Jersey Application June 18, 1938, Serial No. 214,578 In Austria June 25, 3.935?- (ci. tas-2) 2 Claims.

This invention relates to photographic color iilms having sound images therein, and to methods of producing such films.

Development of a sound film to a certain gamma is only a poor compromise. It would be ideal, if the sound track and the image could be developed entirely independent of each other. In the accompanying drawing, the figure vis a flow diagram showing sectional views of successive steps in one method of forming a sound track image according to our invention.

On thin single emulsions drying very rapidly, this may be realized by developing rst only the scenes or the sound track' to the desireddensity, using anti-fogging agents, for example, nitrobenzimidazole and other azimides, triand tetrazoles, thiosemicarbazones. The film is then dried and the other image printed, developed, etc. Variable width recording should be printed and Very thin and weakly tanned emulsions do not have to be dried,

' and the next image may be Aprinted immediately taking ,of the scenes. and the sound record exposed or printed simultaneously or later on the negative'for which also ultraviolet rays or a cathode ray oscillograph may be used.

The lower emulsion may be tanned or `consist of hardened gelatin, and the upper emulsion of soft gelatin. After the imagein the upper emulsion is developed and xed, the sound track in the lower' emulsion layer is developed for a longer time and in a slightly warmed developer or after destruction of the tanning eiect. This lower emulsion layer' may also consist of silver halide collodion emulsion which may have been hardened before coating the upper emulsion layer to make it more diflicultly developable. Both emulsion layers must, of course, be diierently sensitized, or separated from each other by a filter layer, or even dyed, and they are printed from both sides.

A light-sensitive substance, which is not attacked by the developer required for the other after development and washing of the rst image.

Addition of anti-fogging agents is necessary in the second` development.

Double emulsions or those having differently sensitized zones are superior, the scenes being in one emulsion layer or zone and the sound track in the other one, nearest the support. 'I'hin emulsion layersl must be used `to shorten the drying time. The emulsion for the variable width recording may be much thinner and harder than that for the scenes, which should be softer and Aperhaps more sensitive or contain moresilver halide. The two emulsion layers are separated from each other by an easily decolorized yellow iilter layer and printed from diierent sides. The color sensitivity of the emulsion layers may also be diiierent, one for blue-green or yellow, and the other for red or infrared, and they are printed with the corresponding light. Ultraviolet light should be 'used for printing the variable width record on a fine-grain or grainless emulsion. A yellow or colorless ultraviolet-absorbing intermediate layer. must then be present, and the original sound record must be on material which is opaque to ultraviolet rays, for example, on copper ferrocyanide. X-rays may also be used for printing, if the silver halide o f the sound track emulsion has been rsensitized with the thorium salt of eosin, and the original is transparent to X-rays. The variable widthsound rec- A ord should be printed and developed before .the

scenes. If the emulsion forthe scenes is suiliciently sensitive,V it may also be used for direct emulsion layer, is used for 'the sound track. The lower emulsion layer, consisting of gelatin, collodion, etc., may also contain leuco bases, insoluble or at least not noticeably diliusing salts of indigosols, thioindigosols or similar leuco esters, alsovblack or any other colored or colorless substances which do not react during development of the yupper emulsion layer containing the image, and are also unaffected by hypo, as for example,

o-nitrobenzaldehyde, diazo` sulfonic acids and diazo anhydrides with or Without the necessary components. The sound track, is now printed to the desired density from the original or its copy which mustbe'opaque to ultraviolet, using the strong ultraviolet raysl of a mercury quartz lamp. Flnally, the unused bases are washed out in dilute monochloracetic acid, salts of indigosols Vwith cinchonine, triphenylguanidine, diphenylguan-A idine, etc., in-dilute solutions of sodium carbonate, ammonia or sodium hydroxide whichmay have to be prepared with alcohol. hydride is coupled to itself or to the component in ammonia vapors, dilute alcoholic sodium hydroxide, or ammonia; or vapors or `solutions of acetone and ammoniav are allowed to react on the residual o-nitrobenzaldehyde. The lightsensitive substance for the sound track may also consist of mercurio. bromide or other organic salts, and the residue may be blackened after ydevelopment and fixing with sodium sulde.

Emulsions of slight sensitivity of the Lippmann type which 'may be sensitized may also be physically developed'by the Goldberg or Odell methods, but the sound track must be printed corre- Unused any developers than silver bromide.

spondingly longer. Although the scenes developed previously are intensied by this procedure, this effect may be lessened without harm to the film by wiping the lm of! after protecting the sound track.

Two diierent silver halide emulsions are used In which the silver halide of one emulsion layer is more easily developed than that of the other layer. Among the possible combinations are AgCl-AgBr, AgCl-AgI, AgBr-AgI. The rst one appears to'be the best adapted, since silver chloride is much more easily reduced by certain For printing, however, mercurio bromide, silver iodide, and especially silver ferrocyanide, are better'4 suited, because they are much less attacked than silver ferrocyanide, but they cannot, or onlyto a limited degree, be made color sensitive. If a lower silver iodide emulsion layer is combined with a soft upper silver bromide emulsion lsensitized with erythrosine,- and both are separated from each other 'oy an easily decolorized yellow filter or are temporarily colored yellow, the scenes are developed rst in the upper emulsion layer with a weak developer, the residual silver bromide immediately ilxed out, and then the sound track developed in the lower silver` iodide emulsion with a. strong developer and fixed.

A 1% sodium' quinone sulfonate solution and 5% anhydrous sodium sulfite (hydroquinonedisulfonic acid) develops an image on silver chloride gelatin in'a few minutes, but it does not afect overexposed silver bromide after half an hours development. Hydroquinone, pyrocatechin, pyrogallol, amidol, and numerous other developing substances behave similarly under certain conditions which are described in detail in the literature also several simple and compound color developers (Schinzel patent application S, N. 139,758) This difference of developability is less striking in silver chloro-bromide emulsions.

If the original triple-emulsion, however, consists of silver chloride, a fourth lower silver bromide emulsion may be arrangedior the sound track. A film of this type is illustrated in the first stage of the gure of the accompanying drawing in4 which I0 is a suitable transparent support coated with a silver halide layer II of soft gelatin for recording the sound track, and

silver halide layers I3, I4 and I 5 sensitive re` spectively to the'red, green and blue regions of the spectrum and consisting of hard gelatin, all of these layers being separated from the soft gelatin layer Il by a yellow or ultra-violet lter layer I2. The picture area of the illm is exposed none sulfonic acid and sodium sulte on the from the emulsion side to form latent images in the hard gelatin layers and since the film contains the filter layer I2 these images are not recorded on the layer II which is sensitive only to blue light. After exposing or printing of the three separation images on the silver chloride gelatin emulsions, the exposed picture areas may then be developed, as shown in the second stage of the figure to form images I 6, I1 and I8 in the layers I3, Il and I5, respectively, the soundtrack alone being printed dry and through the back on the correspondingly sensitized silver bromide emulsion or on one protected by lters. This emulsion layer is sensitized for infrared or separated from the triple-emulsion by an ultraviolet-absorbing illter, according to whether infrared or ultraviolet-light 'is used for printing. If the picture areas have not been already developed they may be then first developed with quiplaces of the residual silver chloride, coupled with the components in the three-emulsion layers I8 in layers I3, I4, and I5 and sound image I9 in layer Il, as shown in the third stage of the figure, In a variation, one 4may dev elop the residual silver bromide to ,any dye and remove all silver simultaneously with Farmers reducer.

It is, of course, understood that in all materials mentioned in thisl description anti-halation layers must be used, so that very sharp sound records and prints may be obtained.

It is sometimes of advantage to combine some of the methods described with controlled diifusion. 'I'he action may be limited to the outermost layer or zone, if alcoholic solutions of developers or other reagents containing only a few per cents of water are used, so that an independent development of the sound record is guaranteed. Oxidimng agents may also be used in this it is often desirable to reproduce black as a colorr or as silver instead of the subtractive method of superposition of. three dyes, if necessary, for the separation image. This black separation image can be produced relatively simply by processes based on colored development and coupling, Where'the entire silver is still present at the end in the triple or single emulsion, It is only necessary to rehalogenate or to sensitize. The black silver is developed and xed or-A converted to a black dye, and the 'silver thoroughly removed with Farmers solution. In the oxidation methods mentioned in this description, the matter is simple only when silver salts or metallic silver .is still present which may easily be converted into sensitive silver halide or perhaps silver ferrocyanide, after which the procedure is the same as `inst outlined. Otherwise, one is obliged to obtain an insoluble silver halide or silver ferrocyanide by conversion with a silver salt solution, or to impregnate with light-sensitive salts, or to precipitate a silver halide difl'usely through the entire emulsion and to obtain the black image by exposure and development, also colored development, and iixing.

What we claim is:

1. The method of printing the sound track image and picture image on multi-layer photographic material having at least two sensitive layers, an upper layer being composed of soft gelatin containing sensitive silver chloride and a lower layer being composed of harder gelatin containing sensitive silver bromide, which comprises printing the picture image in the layer of soft gelatin, developing it in a weak developer and ixing out the residual silver chloride, and

then printing the sound track image in the layer of hardenpgelaitin, developing it in e. strong developer and xing it.

2. The method of printing a sound vtrack image and a, picture image on-multi-layer photographie y material having atleast one lightsensitive layer of gelatine-silver chloride and at leasfone light sensitive ieyer of gelatina-silver bromide, which comprises printing the sound track image on e, 1o

gelatina-silver bromide Iaxi'erv and the picture i image on mileast one ofthe gelatino-silver ohloi dium quinone sulfonate and sodium suliite developer and then developing the vfgelatino-silver bromide layer in s. developer selected from the group consisting of hydroquinone, pyrocatechin, pyrogallol end amidol,

KARL scmzm..

LUUWIG BCHINZEL.

'ride layers, developing the picture image in a so- 

